1. Field of the Invention
The present invention relates to a rotationally symmetric reflector for use with an incandescent bulb or a discharge bulb, especially a halogen bulb, with a concave reflecting surface of metal, comprising a plurality of plane facets.
2. Background Information
U.S. Pat. No. 5,568,967 describes a concave reflector with a plurality of plane facets, designed to project a rectangular field; because of gaps in the array of facets, optimal efficiency is not possible.
U.S. Pat. 3,511,983 describes a further reflector array with a facet-like configuration of a concave reflector surface.
DE 25 35 174 A1 describes a reflector for selective radiating luminous sources, such as bulbs whose spectrum consists of individual lines or a few narrow bands, wherein the reflector comprises a material of high reflectance and is provided with a protective coating which is devised in such a manner that the interference colors created by the protective coating mix to a white light and unpleasant color effects in the diffused light, which can occur in a line spectrum, are prevented.
The use of such known reflectors has proved to be problematic when they are supposed to function as cold mirrors, in which color conversion toward short-wave light takes place, and given components of the spectrum, such as components of the infrared spectrum and also components of the red spectrum, are to be absorbed, since the mirror of DE 25 35 174 A1 also reflects the red and infrared components respectively of the generated radiation.
U.S. Pat. No. 4,072,856 describes a further reflector array with an interference filter coating.